- Engine Light ON (or Service Engine Soon Warning Light)
- A/C Inoperative
- A/C Blows Warm

- A/C system low or over charge with refrigerant
- Faulty A/C refrigerant pressure sensor
- Cooling fans in-operative
- A/C refrigerant pressure sensor circuit open or shorted

The ECM has detected that the AC compressor clutch cycle rate is high

The powertrain control module (ECM) monitors the high side refrigerant pressure via a A/C refrigerant pressure sensor. When the pressure is high the signal voltage is high. When the pressure is low the signal voltage is low. When pressure is high the ECM commands the cooling fans on. When pressure is too high or too low the PCM will not allow the A/C compressor clutch to engage.